Thank you for your replies. I hadn't thought about the flannel shrinking and therefore tightening the weave. I had not prewashed the fabric because the main part of the quilt was a kit I bought on Ebay. I have added borders which I did not prewash because I assumed the cut pieces had not been. I think for another one I would go with 1/2 inch seams. I think I will quilt over the seams like you suggested, PaperPrincess.